COLLAGEN - ULTRASTRUCTURE AND ITS RELATION TO MECHANICAL PROPERTIES AS A FUNCTION OF AGING
COLLAGEN - ULTRASTRUCTURE AND ITS RELATION TO MECHANICAL PROPERTIES AS A FUNCTION OF AGING
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DOI：
10.1098/rspb.1972.0019
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发表时间：
1972-01-01
期刊：
影响因子：
--
通讯作者：
KELLER, A
中科院分区：
文献类型：
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作者：
DIAMANT, J;ARRIDGE, RGC;KELLER, A
在偏光显微镜下研究了 2 周至 3 岁的 Fischer 和 Sprague-Dawly 白化大鼠的尾腱结构和变形行为。沿着原本毫无特征的肌腱，观察到周期性的熄灭带。通过分析该消光图案在腱适当旋转下的行为，可以推断出基本双折射单元的取向沿着腱周期性变化，并且该周期性图案对应于各向异性实体的平面排列。该周期性结构的所有相关参数可以仅从偏振光学以代表性方式确定。肌腱的细分显示出有规律的起伏或卷曲的亚基，与从完整肌腱的消光带中推断出的结果很好地对应。发现卷曲角度减小，而周期性增加（与尾巴的长度大致成比例），随着大鼠的年龄，卷曲数量在动物的一生中保持恒定。在伸长时，周期性逐渐消除。计算出的消除卷曲所需的纤维伸长率与成熟大鼠的观察结果非常一致，但幼年大鼠的伸长率较大，这意味着纤维本身同时拉伸。测量了肌腱的应力应变特性，并测试了卷曲矫直模型。结果发现，包含刚性铰链的模型（对应于力学中的“弹性”问题）与实验具有合理的拟合度。在此基础上对应力应变数据进行分析，得到一个基本的承载单元，其直径随着动物年龄的增长从 100 纳米增加到 500 纳米。指出了这些发现对肌腱结构和特性的影响，以及与衰老的关系。
Tail tendons from Fischer and Sprague-Dawly albino rats of ages from 2 weeks to 3 years were investigated under the polarizing microscope as regards structure and deformation behaviour. Periodically extinguishing bands were observed along the otherwise featureless tendons. By analysing the behaviour of this extinction pattern under appropriate rotations of the tendon, it could be deduced that the orientation of the basic birefringent units varies periodically along the tendon and that this periodic pattern corresponds to a planar arrangement of the anisotropic entities. All the relevant parameters of this periodic structure could be determined in a representative manner from polarizing optics alone. Subdivision of the tendons revealed regularly undulating or rather crimped subunits in good correspondence to what has been deduced from the extinction bands in the intact tendons. The crimp angle was found to decrease while the periodicity increased - in approximate proportion to the length of the tail - with the age of the rat implying constancy of crimp number during the life time of the animal. On elongation the periodicity was gradually removed. The calculated fibre elongation necessary to eliminate the crimp was in good agreement with observation for mature rats but was larger for young rats implying the simultaneous stretching of the fibre itself. Stress-strain properties of tendons were measured and models for crimp straightening were tested. It was found that a model containing inflexible hinges, corresponding to the ‘elastica’ problem in mechanics gave reasonable fit with experiment. Analysis of stress-strain data on this basis leads to a basic load bearing unit, the diameter of which increases from 100 to 500 nm with the age of the animal. Implications of these findings for the structure and properties of the tendons, also in relation to ageing are pointed out.